Stripped Coupler Bolt - PeachParts Mercedes-Benz Forum

mbboy · #1 12-30-2011, 02:49 PM

After reading everything I could find on replacing a 107 steering coupler, I decided to attack the 6mm, Allen bolt recessed under the firewall with a X-long, ball head hex socket, and ½ in drive with a long extension. However, since the torque on that bolt is evidently far greater than I imagined, I ended up stripping the head.

So, now I’m thinking about gluing a 6mm, Allen socket into the stripped head with JB Weld, and giving it a shot tomorrow. But before I do, I was wondering if anybody here has ever done this, or could speculate what the chances are that it will work. Any other suggestions on how to get the bolt out would also be appreciated.

Thanks very much in advance.

dugald · #2 12-30-2011, 06:00 PM

I can't imagine JB Weld will take the torque.
A real weld would ....

dugald · #3 12-30-2011, 06:02 PM

I think there were some posts on Mercedes-Benz Forum about similar problems.

AlexK · #4 12-30-2011, 06:17 PM

A real weld is the best bet, but make usage of that heat, that is, try to turn it immediately after the welding. Use any hard steel rod to weld on, as a Hex is not strong enough.

RadioTek · #5 12-30-2011, 06:53 PM

When I did the same thing, I ended up taking the steering gearbox out, and sawing on the coupler. I had to saw the coupler along the length of the bolt, literally splitting the coupler to free the bolt.

You have to have the exhaust system loose to get the gearbox in/out.

You need to get new bolts to attach the box to the frame. Special bolts.

You do not need to take the Pittman arm off the gearbox; you can take the other end of the Pittman arm loose from the steering link to free it.

You will want to get new power steering hoses, while you're there, and you have easy access. Crows' Foot wrenches will be invaluable.

You WILL invent new swear words in the process.

Been there. Done that. Got the T-shirt. And the scars.
Scott

AlexK · #6 12-30-2011, 07:20 PM

"You have to have the exhaust system loose to get the gearbox in/out."

That is the part that scares me! You almost have to tighten those exhaust bolts (they have a square head fitting into a ring), to break them off.

If you go the "weld way" than immediately after welding, cool the rod with a wet rag. Done that before.
Remember that the "weld" (according to my welder son) is stronger than the welded pieces.

mbboy · #7 12-30-2011, 09:08 PM

Quote:

Originally Posted by dugald

I think there were some posts on Mercedes-Benz Forum about similar problems.

Yep! Here's what Tony Baroso advised after he stripped the same bolt on his 380sl:

"Get 1/4 inch drill bit and drill extension. Drill deep into cap head but not all the way thru. Heat from drilling 90% of time will allow removal. Insert easy out into tight fitting socket and tape. Use long extension and unscrew mine came right out. If still won't come drill bolts out."

However, I'm still not sure how he got the both the EZ out along with the bolt out of the coupler, considering the lack of room between the coupler and the firewall. Moreover, it seems that the EZ out has to be inserted at an angle, since the bolt is recessed, and people have advised against doing that, for instance, here: EASYOUTS, EASY-OUTS, EZ OUT, EZY-OUT, Bolt Extractor, Screw Extractor

So I'm a little hesitant to go from the frying pan into the fire by, say, having the EZ out break off in the bolt. Ugh!

mbboy · #8 12-30-2011, 09:11 PM

Quote:

Originally Posted by AlexK

"You have to have the exhaust system loose to get the gearbox in/out."

That is the part that scares me! You almost have to tighten those exhaust bolts (they have a square head fitting into a ring), to break them off.

If you go the "weld way" than immediately after welding, cool the rod with a wet rag. Done that before.
Remember that the "weld" (according to my welder son) is stronger than the welded pieces.

Unfortunately, I don't have a welder, and even if I did, I can't see how you could get the tip down far enough to weld a nut onto that bolt? OTOH, I imagine you could weld it on from inside the cabin. So, if I can't do it any other way, maybe I could find a shop that would do the welding for me.

abiby · #9 12-31-2011, 01:07 AM

They make an ezout for allen heads specifically. I bought one a couple years ago when I was in a bind. The info is in this old post of mine.

Useful Tools - Benzworld.org - Mercedes-Benz Discussion Forum

mbboy · #10 12-31-2011, 05:57 AM

Quote:

Originally Posted by abiby

They make an ezout for allen heads specifically. I bought one a couple years ago when I was in a bind. The info is in this old post of mine.

Useful Tools - Benzworld.org - Mercedes-Benz Discussion Forum

Thanks for the suggestion, Abiby. But as far as I can tell, there doesn't seem to be enough room between the coupler and the firewall to get one of these or any other extractor into the bolt head?

rs899 · #11 12-31-2011, 07:18 AM

Ouch. I was just about to tackle this job this week. Maybe I will put it off another year and just tell SWMBO they designed the steering that way...

abiby · #12 12-31-2011, 09:36 AM

Quote:

Originally Posted by mbboy

Thanks for the suggestion, Abiby. But as far as I can tell, there doesn't seem to be enough room between the coupler and the firewall to get one of these or any other extractor into the bolt head?

Obviously the clearance varies from car to car as best I can recall I had no major issues in reaching both coupler bolts from under the hood.

Likewise I don't recall taking a hammer to the firewall to increase the clearance.

meltedpanda · #13 12-31-2011, 10:21 AM

this is not an easy job, and may require some "new tools" such as a 90 degree drill attachement, or a dremmel. the area is tough to work in,
any way you can get to the space the separates the halves and cut the bolt?

abiby · #14 12-31-2011, 01:29 PM

Quote:

Originally Posted by meltedpanda

this is not an easy job, and may require some "new tools" such as a 90 degree drill attachement, or a dremmel. the area is tough to work in,
any way you can get to the space the separates the halves and cut the bolt?

Even with the bolt cut, IIRC the remains of the bolt will be in a groove making removal from the steering shaft difficult though probably not impossible. (I wasn't aware of the groove until I'd forcibly disassembled with the bolts just loosened.

)

I just came in from examining my car and the only thing in the way was the firewall insulating material which I had trimmed slightly to ease access.

I don't know if it would help, but if the bolt on the steering box were removed, could the coupler/shaft be shoved forward enough to get better access? I can't remember but it seems like there was 1/8" - 1/4" clearance between the two shafts, though there might not be that much room on the steering gear end to slide it. Probably a worthless idea, but I thought I'd throw it out there.

3547-fl · #15 12-31-2011, 03:04 PM

Both of my allen bolts were stripped from someone trying to remove it and giving up on it. I drilled out the bolt on the steering box with a 14" drill bit and then removed the steering column and then put the hole assembly on the bench and then drilled the last both out and removed the coupler.
Wished I would had thought of that at first only about 45 min to totally remove the column.